Using the GNUstep MSVC toolchain from MSYS2

The GNUstep MSVC toolchain is a native Windows toolchain, but nothing prevents us from using it from a POSIX shell. This guide is mainly for developers who are used to working in a POSIX environment, and want to use the toolchain from a POSIX shell.

One of the advantages of using the toolchain from a POSIX shell, is that we can use the GNUstep environment variables, and the gnustep-config tool to get the flags needed to compile and link with the GNUstep libraries.

Requirements

First we need to install LLVM, to get the clang frontend, and lld. We will be using Chocolatey to install it, but you can also install it manually using the official installer from the GitHub releases.

We also need to install MSYS2, if not already installed.

In a Administrator Shell (either CMD or Powershell), run the following command:

choco install llvm msys2

Setting the PATH in bash

Before we can use the toolchain, we need to add the LLVM and the GNUstep binaries to the PATH.

I recommend adding the modifications to your ~/.bashrc or ~/.bash_profile. Open a MSYS2 shell (Windows + R -> msys2.exe), and run the following commands:

# Add LLVM and GNUstep binaries to PATH
# The paths may be different depending on your installation
export PATH=$PATH:/c/Program\ Files/LLVM/bin:/c/GNUstep/x64/Debug/bin

# Source the GNUstep environment
source /c/GNUstep/x64/Debug/share/GNUstep/Makefiles/GNUstep.sh

1 Hello World (From the command line)

Open a MSYS2 shell (Windows + R -> msys2.exe), and run the following commands:

# Create a directory for our project
mkdir hello && cd hello

touch main.m

You can now edit main.m with your favourite text editor, and add the following code:

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {
	@autoreleasepool {
		NSLog(@"Hello, World!");
	}
	return 0;
}

Now we can compile the program:

clang -o hello `gnustep-config --objc-flags` `gnustep-config --base-libs` main.m

Or alternatively in two stages:

# --objc-flags: output the flags needed to compile Objective-C code
clang -c `gnustep-config --objc-flags` main.m
# --base-libs: output the flags needed to link with the base library
clang -o hello main.o `gnustep-config --base-libs`

For more information you can run gnustep-config --help. If everything went well, you can now run the program:

./hello
# 2023-10-22 00:33:36.049 hello[5916:12508] Hello, World!

2 Using the toolchain without MSYS2

Using a POSIX shell is great for developers accustomed to UNIX-based systems, but not natural in the Windows world. If you want to integrate GNUstep into a Visual Studio, or other build system, the best way is to specify the flags manually.

For more information on how to use the toolchain in Visual Studio, see Using the toolchain in Visual Studio in the projects GitHub readme.